Hydraulically operated valve device



July 3. 1956 R. STEVENSON 2,753,414

HYDRAULICALLY OPERATED VALVE DEVICE Filed May 5, 1955 IN V EN TOR.

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United States Patent Robert Stevenson, Wickford, R. 1., assignor toMagnetic Seal Corp., a corporation of Rhode Island Application May 5,1955, Serial No. 506,113

8 Claims. c1. zoo-s2 This invention relates to a hydraulically operatedvalve device, particularly adapted for opening and closing an electricswitch.

An object of this invention is to provide a hydraulically operated valvedevice having a fluid pressure operated valve closure adapted to bemoved to closed and open position at predetermined high and low fluidpressures.

Another object of the invention is to provide a hydraulically operatedvalve device having a valve closure which upon being moved to closedposition will remain closed and be moved to open position at apredetermined low fluid pressure very much less than the closingpressure.

Another object is to provide a hydraulically operated valve device foropening and closing an electric switch.

Another object of the invention is to provide a hydraulically operatedvalve device having a pressure operated valve closure provided withpressure applying areas thereon such as to be unbalanced to a forceacting thereon in a direction to urge the closure to closing positionand in which said pressure applying areas upon initial closing movementof the said closure will be further unbalanced in a direction toincrease the effects of the said force acting thereon in the directionto move the closure to closed position.

With these and other objects in view, the invention consists of certainnovel features of construction as will be more fully described andparticularly pointed out in the appended claims.

The figure of the drawing is a longitudinal sectional view through ahydraulically operated valve device embodying my invention.

Referring to the drawing in more detail, 10 designates generally acasing in which there is formed a generally rectangular cavity orchamber 11 and three vertical bores 12, 13, 14 in which are housed valvemechanism 15, 16 and a pressure applying lunger 17, respectively. Theaxes of the bores are parallel and in the same plane and are reduced orenlarged along their lengths to the extent corresponding to theparticular parts of the mechanism interfltting therewith as willhereinafter appear. A lateral bore 13 extends from a pressure port 19laterally across a reduced bore portion 29 of bore 12 and opens into thelower portion 21 of the enlar ed portion of bore 13. A lateral bore 22extends from the larger portion 23 of bore 12 to the lower end extremityof the reduced portion 24 of the bore 14 and forms with bores 18, 23,and 22 a first passageway designated generally 25 from the port 19 tothe bore The bore portion 23 is made larger than bore portion 2% andforms an annular valve seat 26 at the junction therewith.

The lower end portion of bore 13 is reduced as at 27 to form an annularvalve seat 28 at the junction of the bore portions 21 and 2.7. The boreportion 27 opens into the bore 22 and forms with cores 18, 21, 27, 22 asecond passageway designated generally 29 from port 19 to the bore 24.

The port 19 is adapted to be connected to a fluid pressure source whichis to be controlled. The flow of fluid 2,753,414 Fatented July 3, 1956past valve seat 26 is controlled by the mechanism 15 which is composedof a conical valve closure 30 adapted to engage against valve seat 26 toblock the flow past the seat 26. The closure 30 has a stem 31 which isslidably received in bore 20 and is reduced between the ends thereof toprovide a neck portion 32 which is at a position to intersect bore 18and permit the flow of fluid past the said stem from the port 19 throughthe second said passageway 29. The stem 31 above the neck portion 32 issealed against leakage by a seal 33 which surrounds said stem. A hollowpiston 34 having an open upper end is slidably received in the bore 12and has a depending stem 35 which slidably extends into the bore portion20 into en agement with the stem 31. Within the bore 12 is arranged acompression spring 36, the lower end portion of which is received in thehollow of piston 34 to abut against said piston and the other end ofwhich abuts against a plug 37 which is screw threaded to the wall of theupper portion of the bore 2 for adjustment of the pressure of spring 36.The stem 35 is thus held in engagement with the stem 31 and by adjustingthe plug 37, the bias pressure applied to the closure 30 tending to movethe same from valve seat 26 can be altered as desired.

The closure 30 is provided with a projecton 38 which, in the openposition of closure 3%, abuts against the upper flat surface of a plug39 which spaces the lower end of the closure therefrom to expose thesame to fluid pressure from port 19. When the closure 3t"; is in theopen position as shown in the drawing, the surface areas thereof exposedto pressure from port 19 are such as to provide an unbalanced forceacting on the closure 30 in a direction tending to move the same to seat26. The area of the closure 30 exposed to this force is an area equal tothe area of the valve stem 31 minus the end surface area of projection38 which contacts plug 3%. This force is opposed by the bias of spring36 tending to move the closure to open position. Thus, the area exposedto this force may be increased or decreased by a choice of end surfacearea of the projection 38. The pressure of spring 36 may be adjusted topredetermine the force required for closing the closure 38. It may bepointed out that upon the closure 39 being separated from the plug 39 toex ose the surface area of projection 33, the surface area exposed to aforce tending to move the closure 30 to its seat 26 is increased by thearea of projection 33 times the pressure of the liquid, and thisincrease in surface area produces a quick closing movement of closure39.

The flow of fluid from port 19 through the second passageway 23 to bore24 is controlled at the valve seat 28 by the valve mechanism 16 whichhas a hollow valve head provided with a conical end 41 which is normallyengaged against valve seat 28 to block the flow of fluid therethrough tobore 24. The head it) has generally radial openings which extendinwardly to the hollow of the head. These openings form conduits for thepassage of fluid to the upper end of said valve head 40. in the bore 13is arranged a compression spring 43, one end of which abuts against thehead 40 within the hollow thereof and the other end of which abutsagainst a plug 44. The plug 44 is screw threaded in the bore 13. Thus,by adjusting the plug 44, the bias of spring pressure applied on thevalve head 40 can be altered as desired.

When the head 40 is seated, the surface areas thereof exposed topressure from port 19 through bore 18 are such as to provide a forceacting on the valve head 40 in a direction tending to move the sametoward its seat 23. The area of the valve head exposed to this force isan area equal to the area of the bore 21. The surface area of the valvehead 40 exposed to pressure of the fluid in bore 22 is such as toprovide a force acting on the valve head 40 in a direction tending tomove the valve head from seat 28 when the valve 30 is open. The area ofthe valve head exposed to this force is an area equal to the area of thevalve seat 23. The difference of the areas of .bore 21 and valve seat 28times the pressure is the pressure exerted to close the valve head 40.

The plunger 17, the purpose of which will hereinafter appear, iscomposed of a cylindrical head 45 which is received in the bore 14 andhas a stem 46 slidably projecting in the reduced bore portion 24. Thestem 46 is sealed against leakage past the same by an O-ring 47. In thebore 14 there is positioned a compression spring 48, one end of whichabuts against the head 45 and the other end of which abuts against theend wall 49 of the said bore 14. Thus, a bias is provided on the plunger17 tending to move the same against a stop shoulder 50 which is formedat the junction of the bore 13 and reduced bore portion 24 thereof. Thefluid pressure acting against the end of the stem 46 is opposed by thepressure of spring 48.

Within chamber 11 there is positioned the electric switch S to becontrolled by the mechanism hereinabove described. The switch S may beof any approved manufacture and is illustrated more or lessconventionally having a body 51 secured to the walls of the chamber asby fastening indicated 52. The switch S has a push button 53 which whendepressed will open the switch contact (not shown). The switch contactsmay be connected by leads 54, 55 to the particular electric circuitcontrolled by the said switch S. The leads 54, 55 pass outwardly of thesaid chamber 11 through an opening 56 in the chamber wall.

There is secured to the piston 34 a pin 57 which projects therefrom intochamber 11 through an elongated opening 58 in the wall of the casingseparating the bore 12 from the chamber 11. The pin 57 is at a locationopposite to the button 53 and has an inclined cam surface 59 whichengages the said button. The relation between the said pin and button issuch that when the valve 15 is in the open position, as shown in thedrawing, the button 53 will be in the extended position and the switch Swill be in the closed position. Upon the seating of valve 15, the pistonwill have moved upwardly, carrying the pin therewith, and the camsurface 29 thereon will have engaged the button to retract or move thesame inwardly of the switch body and open the electric contacts of theswitch.

The electric switch operating device hereinabove described is adaptedfor use in various hydraulic systems wherein the pressure of a supplysource may be electrically controlled. As by way of example, assume thedevice is to be employed for controlling a fluid supply source to anaccumulator (not shown) and said supply source is an electric motordriven pump (not shown). Assume the port 19 connected to the accumulatorand the switch S connected in the electric circuit of the motor of thepump. Further assume the fluid supply to the accumulator is to be shutoff upon a pressure of 3,000 pounds at the accumulator and the supply isto be turned on upon a pressure drop to 1,000 pounds at the accumulator.The valve closure 30 is in the normal open position and fluid will flowfrom port 19 to plunger 17, the spring bias of which is predetermined toyield at a pres sure in excess of 1,000 pounds thereon. Fluid from port19 will flow through bore or conduit 18 to bore portion 21. The pressurein conduit 18 is that of pressure in conduit 22, and the valve head 40will be in balance to this pressure, since the opposite areas exposed tothis pressure are equal to each other.

Upon the pressure of port 19 reaching 3,000 pounds, this force will acton closure 30 as hereinabove described and overcome the resistance ofthe bias of spring 36 thereon, which has been adjusted to yield at 3,000pounds. The closure 30 will move to engage seat 26 and block the flow offluid through the passage 25 to the plunger 17. As the closure 30 ismoved to seat 26, the piston 34 will move upwardly and the cam surfacewill move the button 53 inwardly of the switch to open the electriccontacts thereof and thus open the said motor circuit (not shown). Thefluid in conduit 22 will be trapped between the plunger 17 and the valveseat 26 and be under pressure of the force of spring 48. The pressure ofthe fluid trapped in bore 22 of passageway 25 is that of the pressure ofthe fluid at port 19 at the closing of closure 30, and this pressure ismaintained in bore 22 by the plunger 17 under bias of spring 43. Thesurface area of closure 30 now exposed to the pressure in bore 22 actingthereon in a direction tending to move the closure 30 seated is asurface area equal to the area of the valve seat 26. Thus, the eflectivearea on closure 30 has been increased by an area equal to the surfacearea of projection 38. When the closure 30 is seated, the surface areasthereon exposed to pressure of port 19 fluid are such as to provide abalanced force acting on the valve closure on the port side thereof. Ashereinabove described, the opposite eflective surface areas on valvehead 40 exposed to fluid pressure of bores 18 and 22 are equal to thearea of valve seat 28 and thus the forces of the fluid acting on thevalve head 40 are in balance. The bias of spring 43 is set to yield whenthe pressure in bore or passageway 29 drops to 1,000 pounds.

Upon a drop in pressure of fluid from port 19 to 1,000 pounds, thespring 43 will yield and valve head 40 will move to open position underfluid pressure in bore 22 due to spring 48 and vent the same, droppingplunger 17 to its shoulder 50. This will dissipate the pressure actingon closure 30, and the same will move to open position under urge of thebias of spring 36. The opening of closure 30 will move the piston 34downwardly and move the cam surface 59 to a position to permit thebutton 53 to move outwardly of the switch body to cause the electriccontacts thereof to be moved to closed position and close the electriccircuit controlled thereby and resume supply of fluid to theaccumulator, after which head 40 will close and pressure will be builtup again and supplied to conduit 22 to again raise plunger 17 to thefull line position shown.

From the hereinabove description it will be readily seen that the valvemechanism 15 operates to shut off a fluid pressure supply at a highpressure and that valve mechanism operates to resume the supply at apredetermined low pressure. It also will be readily seen that there maybe a very wide difference between the closing and opening pressures.

The valve controlled device has been described in an embodiment forcontrolling the opening and closing of an electric switch. However, itwill be readily apparent that the device may be adapted to othersituations wherein a great difference may be required in the opening andclosing pressures of the valve device.

I claim:

1. A hydraulically operated valve device comprising a casing having aport adapted to be connected to a fluid supply source under pressure, aresiliently mounted plunger in said casing, a first passageway leadingfrom said port to said plunger, fluid pressure responsive valve means insaid first passageway for controlling the flow of fluid to said plunger,said means normally being in the open position thereof, a secondpassageway leading from said port to said plunger, a second fluidpressure responsive valve means in said second passageway forcontrolling the flow of fluid between said port and said plunger, saidsecond valve means being normally in closed position to blockcommunication between said port and said plunger, whereby upon movementof the first said valve means to closed position under pressure of thefluid from said port, the fluid in said first passageway will be trappedbetween said first valve means and said plunger and be under pressure ofsaid plunger to act on said first valve means to hold the same in theclosed position.

2. A hydraulically operated valve device as set forth in claim 1 whereinsaid second valve means include a valve closure having pressure applyingsurface areas thereon exposed to the fluid pressures in said passagewayssuch as to provide a balanced pressure force acting thereon.

3. A hydraulically operated valve device as set forth in claim 1 whereinsaid first valve means include a closure having a resilient bias thereonacting thereon in a direction to oppose closing movement thereof andsaid plunger has a bias thereon of a force to maintain said fluid at theclosing pressure of said first valve means.

4. A hydraulically operated valve device comprising a casing having aport adapted to be connected to a fluid supply source under pressure, aresiliently mounted plunger in said casing, a passage leading from saidport to said plunger, pressure responsive valve means for controllingthe flow of fluid from said port to said plunger, said valve means beingnormally in the open position thereof and moved to closed position upona predetermined pressure of said fluid to trap the fluid in saidpassageway between the said valve means and the said plunger whereby thefluid trapped in said passageway will be under pressure of said plungerto act against said valve means to maintain the same in the closedposition, and means operable upon a predetermined drop in pressure atsaid port to vent said passageway and permit the valve means to returnto open position.

5. A hydraulically operated valve device comprising a casing having aport adapted to be connected to a fluid supply source under pressure, aresiliently mounted plunger in said casing, a first passageway leadingfrom said port to said plunger, a valve seat in said passageway, anormally open fluid pressure responsive closure for said valve seat andhaving pressure applying surface areas thereon exposed to the fluidpressure in said passageway such as to provide an unbalanced forceacting on said closure in a direction to move the same on to said seat,means for applying a resilient bias on said closure for opposing saidforce, a second passageway leading from said port to said plunger, asecond valve seat in said second passageway, a second pressureresponsive valve closure for said seat and resiliently biased formovement toward said second seat, said second closure having pressureapplying surface areas exposed to the pressures in said passageways suchas to provide a balanced force acting on said second closure wherebysaid bias thereon will hold said second closure normally seated andblock communication between said port and said plunger where upon thefluid pressure acting on the said first closure overcoming the said biasthereon to move the said first closure to seated position, the fluid insaid first passageway will be trapped between the first valve seat andsaid plunger and be under pressure of said plunger to act against saidfirst closure to hold the same seated against said bias thereon.

6. A hydraulically operated valve as set forth in claim 5 wherein anabutment is provided in said first passageway and said first closure hasa projection thereon extending into engagement with said abutment whensaid closure is in open position, whereby upon closing movement of saidclosure said projection will be spaced-from said abutment and theeffective areas on said closure ,eX- posed to fluid pressure in saidfirst passageway will be increased by a surface area equal to thesurface area at the end of said projection.

7. A hydraulically operated valve device comprising a casing having aport adapted to be connected to a fluid supply source under pressure, aresiliently mounted plunger in said casing, a first passageway leadingfrom said port to said plunger, fluid pressure responsive valve means insaid first passageway for controlling the flow of fluid to said plunger,said means being normally in the open position, a second passagewayleading from said port to said plunger, a second fluid pressureresponsive valve means in said second passageway for controlling theflow of fluid between said port and said plunger, said second valvemeans being normally in closed position to block communication betweensaid port and said plunger, whereby upon movement of the first saidvalve means to closed position under pressure of the fluid from saidport, the fluid in said first passageway will be trapped between saidfirst valve means and said plunger and be under pressure of said plungerto act on said first valve means to hold the same in the closedposition, and an electric switch connected to said first valve means andmoved to a closed and open position upon movement of said valve means toand from open position.

8. A hydraulically operated valve device as set forth in claim 7 whereinthe connection between the said switch and said first valve meansincludes a cam carried by said first valve means and extending therefrominto engagement with said electric switch.

No references cited.

